Let a e R which expressions are correct? and give the justification why they are part of the Borel o-algebra, B(R) {a} 1 a+ a nEN Q = U {a;}, a; is rational ieN

Assume that [a],[b] is an element of (Z12 ,circle plus), order of ([a])=m, order of ([b])=n. Find examples of [a] and [b] (one example for each case, so three examples) for which order of ([a] circle plus [b])=mn, order of ([a] circle plus [b])=lcm(m,n) doesnt equal mn, and order of ([a] circle plus [b]) doesnt equal mn and order of ([a] circle plus [b]) doesnt equal lcm(m,n)

O fb822ce4-4bd3-43cc-b105-cc74 x + Question: In the ring 7L8 [x]. Show thet 1+2x is a Unit. + GB V A 22:18